B4X

Upload to an SFTP Server Using an Open Handle

Demonstrates the Chilkat SFtp.UploadFile method, which streams a local file to a remote file identified by an open handle. The first argument is the handle (from OpenFile) and the second is the local file path. Close the handle with CloseHandle when done.

Note: This example uses relative local paths, which are resolved against the application's current working directory. Absolute local paths may also be used. Supply the paths appropriate to your own environment.

Background: This is the lower-level upload, useful when you need control that UploadFileByName does not offer — for example choosing the exact create disposition (create-new versus truncate versus append) via OpenFile, or reusing a handle across operations. The transfer itself is streamed and unbounded by memory. The trade-off is that you own the handle's lifetime and must close it explicitly.

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Dim success As Boolean = False

'  Demonstrates the SFtp.UploadFile method, which streams a local file to a remote file that is
'  identified by an open handle.  The 1st argument is the handle and the 2nd is the local file
'  path.

Dim sftp As ChilkatSFtp
sftp.Initialize("sftp")

'  Connect, authenticate, and initialize the SFTP subsystem.
Dim port As Int = 22
success = sftp.Connect("sftp.example.com", port)
If success = False Then
    Log(sftp.LastErrorText)
    Return
End If


'  Normally you would not hard-code the password in source.  You should instead obtain it
'  from an interactive prompt, environment variable, or a secrets vault.
Dim password As String = "mySshPassword"

success = sftp.AuthenticatePw("mySshLogin", password)
If success = False Then
    Log(sftp.LastErrorText)
    Return
End If


success = sftp.InitializeSftp
If success = False Then
    Log(sftp.LastErrorText)
    Return
End If


'  Open (creating/truncating) the remote file for writing.  OpenFile returns a handle string.
Dim handle As String = sftp.OpenFile("subdir/report.pdf", "writeOnly", "createTruncate")
If sftp.LastMethodSuccess = False Then
    Log(sftp.LastErrorText)
    Return
End If


'  Stream the local file to the open remote handle.  The transfer is not limited by memory.
success = sftp.UploadFile(handle, "qa_data/report.pdf")
If success = False Then
    Log(sftp.LastErrorText)
    Return
End If


'  Close the remote handle when the upload is complete.
success = sftp.CloseHandle(handle)
If success = False Then
    Log(sftp.LastErrorText)
    Return
End If

Log("Uploaded.")

sftp.Disconnect